[FONT=verdana,geneva]Portable Coop Design by Pam Williams[/FONT]First off, I have to give credit where credit is due - almost ALL of this design incorporates the suggestions from the posts on the "Things I Learned While Building A Coop" forum/thread. Many thanks go to the considerate people who shared their stories and whoopsies with the rest of us so that we would be spared a common fate. This is a WIP (work in progress) as I am also working two jobs and trying to get the outside of my house painted (at least the front to avoid embarrassment with my neighbors).
I began with two pallets of equal size, screwed them together, then tacked down 1/4" hardware cloth to cover the pallets (to thwart predators). I then covered that whole thing with a layer of plywood - I used 5 mm to keep the coop light, but you can use any thickness. I drilled holes and then installed eyebolts at each corner (keeping them about 2" in from the corners) on the ends of the base to aid in lifting.
Using the 1x3s, I made a frame around the perimeter of the base, using 1x2 stock to help anchor it to the floor. Screw the 1x3s together at the corners, then fit the 1x2s to the inside, screw them to the floor, then screw the 1x3s to the 1x2s. You could use 1x1 stock if you can find it. I then started adding the vertical corner stock, screwing them to the inside of the base, using two at each corner in an "L" design, screwing them together at about 12" intervals. I then realized that the outside wouldn't be flush for the outside walls, so I added more stock to each corner on the outside to strengthen and even out the framing.